Thymic stroma-derived T cell growth factor (TSTGF): III. Its ability to promote T cell proliferation without stimulating interleukin 2- or 4-dependent autocrine mechanism.
A thymic stroma-derived cell clone, MRL104.8a produced a T cell growth factor designated as thymic stroma-derived T cell growth factor (TSTGF). This factor that is distinct from previously described T cell growth factors such as interleukin (IL) 2 or 4 was capable of promoting the growth of IL2-dependent, antigen-specific helper T cell clones. While such growth promotion was induced without requirement of the relevant antigen and exogenous IL2, we further investigated whether it depended on activation of an IL2- or IL4-dependent autocrine mechanism. Helper T cell clones, 8-E and 8-5, were able to proliferate in response to stimulation with either antigen or TSTGF. 8-E and 8-5 produced IL2 and IL4, respectively, in cultures following antigenic stimulation, whereas neither IL2 nor IL4 activity was detected in cultures during TSTGF-induced proliferation. The proliferation of these helper T cell clones by antigenic stimulation was almost completely inhibited when anti-IL2 receptor or anti-IL4 antibody was added to the cultures. The addition of cyclosporin A (CsA) to cultures of 8-E and 8-5 clones together with antigen also resulted in the complete inhibition of cellular proliferation in association with the suppression of IL2 and IL4 production. In contrast, TSTGF-induced proliferation was not affected by addition of either type of antibody or CsA. These results indicate that TSTGF is a novel T cell growth factor that can exert its own growth-promoting effect without depending on an IL2- or IL4-operating autocrine mechanism.
Kosaka
H
H
Biomedical Research Center, Osaka University Medical School, Japan.
Ogata
M
M
Sano
H
H
Sakuma
S
S
Mizushima
Y
Y
Nakamura
E
E
Teraoka
H
H
Hamaoka
T
T
Fujiwara
H
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003524:Cyclosporins / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003524:Cyclosporins; D007376:Interleukin-2; D015847:Interleukin-4